Question

Why do ice cream sellers sprinkle salt on ice?

Answer 1

to lower the melting point of the ice cream?

Answer 2

I'd have to go with @chenping ... I'm not sure! I mean, salt trucks will sprinkle salt onto roads so that the water will have a lower freezing point. This concept is called "freezing point depression."

I think salt is an ingredient in ice cream...

Answer 3

Here's a good link, maybe!

http://curiosity.discovery.com/question/why-there-salt-ice-cream

I think that might answer your question..

Answer 4

Does it means that temperature of ice at 0 degrees will go down if we sprinkle salt on it. How can that be? Why would ice release heat when we put salt?

Answer 5

@theEric @Vincent-Lyon.Fr

Answer 6

Hello! Nope, the temperature will be the same, but the new "solution" will behave differently. The new "solution" or ice cream stuff will now \(\color{red}{not}\) freeze at the same temperature, the freezing point becomes lower. So ice cream can be not frozen even at freezing temperatures. I put ice cream in my freezer and it's still a little soft when I pull it out. The water that I put in the ice trays is frozen solid. That's the difference between the freezing points!

Answer 7

Same temperature, different freezing points, different behaviors at different temperatures.

Answer 8

Wait! I think people put salt in water to form brine and not on frozen ice because it will melt it. Just like the snow on roads. So, they initially build a brine solution and then try to freeze it. It will now no longer freeze at 0 but at -10 or some other temperature depending upon the concentration of brine. So, ice will form at lower temperature and will be colder and hence will freeze the ice cream mix. All this is done to get "colder ice" by lowering its freezing point so that it can freeze ice cream mix.

Answer 9

Now i have another confusion. Why don't they simple superfreeze the "normal ice" to sub zero temperature (-10 or something) and then use it. Instead of going through all this complicated process and wasting salt.

Answer 10

Adding salt to ice cubes (at 0 °C) will melt the ice until a new equilibrium temperature is reached. (melting ice absorbs energy, so temperature goes down). You can easily reach -12 °C which is perfect for nice soft ice-cream.

This can be a good way to keep your ice-cream refrigerated without a power supply and a freezer.

Of course you do not add the salt to the ice-cream itself!